Many products which utilize the photocatalytic activity of titanium dioxide for an antibacterial, anti-odor, stain resistant, or other effect are being marketed. Further, using a titanium base material and combining the anodic oxidation method and heating in an oxidizing atmosphere to express photocatalytic activity is disclosed in PLT 1. Furthermore, PLT 2 discloses a titanium-based metal material which has a superior photocatalytic activity by deposition of a film containing titanium oxide powder on an anodic oxidation layer.
These titanium-based materials which have photocatalytic activity can be used even in various types of corrosive environments since the base materials are titanium with its extremely superior corrosion resistance and are being worked into various shapes for use in accordance with various applications such as building materials, vehicle outer panels, household electric appliances, etc.
Further, PLT's 3 to 5 disclose forming titanium oxide into a mesh-shaped structural member and utilizing its photocatalytic activity for the purification, sterilization, etc. of sea water, wastewater, fresh water, etc.
Furthermore, PLT 6 and PLT 7 disclose performing anodic oxidation in a bath to which a powder of titanium oxide has been added so as to obtain titanium particles which have photocatalytic activity. These titanium particles which have photocatalytic activity are combined with a binder and coated for utilization for improvement of the stain resistance, antibacterial property, etc. of various base materials.